Tuning FX CROWN .30 WANTING TUNING ADVICE PLEASE

I use a 7gm weight for .22 slugs, though my .30 barrel has been taking it's time in the snail mail. I think it will shoot 900 or so fps at 150 bar or so with the weight. But again, have not been able to test because my barrel has been delayed 

you may want to use a slightly smaller valve seat. I am going to try and use 6.5 on mine, but have modified the valve seal to be larger than factory.... I am anticipating some issues with it, however.

Remove stock and increase hammer spring tensioner to within 1 quarter-turn away from max. Replace power wheel and turn it to max. Fill with air, load magazine, and fire over chronograph watching fps. With a regulator pressure of 165 bar, you're probably going to want to try decreasing pressure before increasing(MK1 crowns usually match max hammer spring tension at 120 to 140bar, but your gauge may be off). Decrease regulator(clockwise) a quarter turn. Dry fire 2 or 3 times or until reg pressure needle stablizes. Then fire over chrono again. Now follow this:

If fps increases(which it should), the continue to lower reg pressure 1 quarter turn at a time. Continue decreasing reg pressure 1 quarter turn at a time(and dry firing a couple shots to stabilize reg), until fps decreases, then increase reg 1 quarter turn.

If for some reason fps decreases, then begin increasing reg pressure 1 quarter turn at a time and then firing over chrono. Repeat until chrono fps starts to decrease. Then decrease regulator 1 quarter turn.

Fire several more shots over chronograph to verify consistent fps. This is your (nearly)max power. 

At this point, smaller turns on the regulator (increasing or decreasing) may "fine tune" your max power.

Replace stock and shoot on different power wheel/transfer port settings to determine most accurate setting for your prefered ammo. And I would recommend indexing the liner in the upward direction if you haven't already. 

This is results in a tune that will give you the ability to use all barrels/calibers and help reduce variance in extreme spreads over your shot string.

Good luck